Mitral valve replacement in infants and children 5 years of age or younger: evolution in practice and outcome over three decades with a focus on supra-annular prosthesis implantation.
OBJECTIVE
Successful mitral valve replacement in young children is limited by the lack of small prosthetic valves. Supra-annular prosthesis implantation can facilitate mitral valve replacement with a larger prosthesis in children with a small annulus, but little is known about its effect on the outcomes of mitral valve replacement in young children.


METHODS
One hundred eighteen children underwent mitral valve replacement at 5 years of age or younger from 1976-2006. Mitral valve replacement was supra-annular in 37 (32%) patients.


RESULTS
Survival was 74% +/- 4% at 1 year and 56% +/- 5% at 10 years but improved over time (10-year survival of 83% +/- 7% from 1994-2006). Factors associated with worse survival included earlier mitral valve replacement date, age less than 1 year, complete atrioventricular canal, and additional procedures at mitral valve replacement, but not supra-annular mitral valve replacement. As survival improved during our more recent experience, the risks of supra-annular mitral valve replacement became apparent; survival was worse among patients with a supra-annular prosthesis after 1991. A pacemaker was placed in 18 (15%) patients within 1 month of mitral valve replacement and was less likely in patients who had undergone supra-annular mitral valve replacement. Among early survivors, freedom from redo mitral valve replacement was 72% +/- 5% at 5 years and 45% +/- 7% at 10 years. Twenty-one patients with a supra-annular prosthesis underwent redo mitral valve replacement. The second prosthesis was annular in 15 of these patients and upsized in all but 1, but 5 required pacemaker placement for heart block.


CONCLUSIONS
Supra-annular mitral valve replacement was associated with worse survival than annular mitral valve replacement in our recent experience. Patients with supra-annular mitral valve replacement were less likely to have operative complete heart block but remained at risk when the prosthesis was subsequently replaced.
Selamet Tierney
Elif Seda
ES
Department of Cardiology, Children's Hospital, Boston, Massachusetts 02115, USA.
Pigula
Frank A
FA
Berul
Charles I
CI
Lock
James E
JE
del Nido
Pedro J
PJ
McElhinney
Doff B
DB
D000367:Age Factors; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008943:Mitral Valve / Q000002:abnormalities*; D008944:Mitral Valve Insufficiency / Q000151:congenital / Q000401:mortality / Q000601:surgery*; D008946:Mitral Valve Stenosis / Q000151:congenital / Q000401:mortality / Q000601:surgery*; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000401:mortality; D011336:Probability; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome